In general, a vehicle is classified into a frame type vehicle mid a monocoque type vehicle.
A frame type of vehicle is provided with a frame as a basic chassis and allows saving cost by expansion of modularization and ride performance by isolating vibration due to the frame and a bush of a car body, whereas a monocoque type of vehicle has a low floor, such that it is possible to reduce the height of the vehicle from the ground, improve roll performance, and develop stylish vehicles.
By applying the characteristics of the frame type and monocoque type as described above to a vehicle, that is, when a frame is applied to a vehicle that is designed for the monocoque type, it is possible to simultaneously obtain the advantages of a frame type of vehicle and a monocoque type of vehicle as well.
However, when a frame is applied to a vehicle, it needs to reduce the size of the frame. Therefore, it is required to manufacture a small-sized frame, which causes limitation on the weight and cross section of a car body. Accordingly, the small-sized frame has smaller dynamic stiffness at the connection portion of a trailing arm mounted to the fame than a large frame having sufficient weight and cross section.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art that is already known to a person skilled in the art.